Due to their rapidly increasing value, incidents of tampering and/or removal of metal conductors, such as copper or aluminium, in metallic infrastructures such as telecommunications sites and transport sites have risen steadily over recent years, and are thus becoming a problem worldwide.
Additionally, being able to monitor for natural degradation in metallic conductors, due to corrosion or accidentally inflicted damage, would be beneficial.
In an attempt to combat the widespread theft of such metallic conductors, a number of solutions have been proposed. These solutions can generally be divided into three categories: prevention of thieves or unauthorised persons getting onto or into the site; detection of thieves or unauthorised persons whilst on the site; and catching the thieves or ‘handlers’ receiving the illegally removed materials after the event.
Prevention typically includes security fencing, including electric fencing, but has not proved effective in preventing entry of determined thieves.
Detection primarily utilises established ‘traditional’ security technology for detecting thieves when on site. The technology used is predominantly Monitored CCTV, Movement and Sound Sensors. Monitored site CCTV can provide notice of thieves on site, but does not confirm what has been removed. Furthermore, it is also still prohibitively expensive for most sites. Devices such as movement and sound sensors are prone to false alarms in such site environments, due for example to animals passing through the site, which adds to operational costs and inconvenience.
The third approach is to ensure capture of the thieves or handlers after the event. The most established approaches and technologies in this area are: SmartWater® which provides invisible traceability of the material stolen and has proved very effective in addressing the resale of the stolen materials; printing the owner identification on the sheathing/casing, which is a deterrent but as a common practice can be burnt off; and ‘Land Mines’ containing visible and/or invisible dye and which detonates upon being disturbed when thieves are in unauthorized areas. This latter arrangement is a recent development which again will aid in the identification of thieves.